Dr. Howard Chen, our Fire Safety Director brings you the 4th installment of our fire safety features some crucial information on fire performance attire. Fire Performers are no different than performers of other arts in that they seek well made, protective clothing and costumes when they’re practicing or performing their art. So let’s talk about what makes fibers, threads, fabric, and costumes more or less fire retardant.
Fabric Fire Retardant Qualities Overview
There are several considerations when utilizing fabrics for their fire retardant / fire resistant properties – namely:
- number one – the fiber content
- number two – the fabric weight and weave, and
- number three – the fit and the finish of the clothing
Terms: Fire Proof, Fire Retardant vs. Fire Resistant
Before we get started with the details, I’d first like to address a common term which I think is used incorrectly. It’s the term, “Fire Proof”. Unfortunately, in the world of fire performance, there is NO such thing as “Fire Proof”. It doesn’t exist in cloth, or a “fireproofing” spray, or any other barrier method. Unfortunately, the truth is that everything will burn or melt or degrade at some temperature, given a long enough duration of exposure to fire.
We should also clarify the terms “Fire Retardant” vs. “Fire Resistant”. By definition, a fire retardant is a physical or chemical agent that reduces the flammability of a material. Fire Resistance is a measure of how long a substance can resist ignition or damage from being exposed to fire.
Of the components of a fabric that determine it’s fire resistance, the fiber content, meaning what the threads are actually made of, is probably THE most important factor. Fibers that make up clothing can generally be divided into two categories – Natural Fibers from plants and animals, and Synthetic Fibers, which are generally petroleum based. Examples of “natural fibers” include leather, cotton, wool, silk, hemp, and bamboo. Examples of TRADITIONAL Synthetic Fibers include nylon, polyester, acrylic, and rayon. A NEWER category of synthetic fibers, called the “Aramids”, include fibers familiar to fire performers, such as – Kevlar™, Nomex™, PBI, and Carbon-X™.
Natural vs. Traditional Synthetic Fibers
Let’s compare the natural vs. traditional synthetic fibers. In general Natural fibers don’t catch fire easily, and don’t melt. When they’re burned, they turn to ash. In comparison, however the traditional synthetic fibers burn more easily, and most importantly, they can also melt. And When they melt, they carry the heat that it took to melt the fibers directly onto your skin, and hold it there. This sounds like a good setup for a severe burn, and unfortunately, it is. If that wasn’t bad enough, the traditional synthetic fibers also create and hold on to more static electricity, which, in the context of working with flammable fuels and vapors, can create an unwanted ignition risk.
Fiber and Fabric Blends
Let me mention a bit about about blended fibers and blended fabrics. Unfortunately, fibers that are inherent blends of natural and synthetic components, such as rayon, burn and melt just like traditional synthetic fibers.
Now, if we talk about fabric and clothing made of different types of fibers, like an 80/20 blend of Cotton and polyester, which you might find in a common T-shirt, you can expect that this kind of blended fabric will have fire resistance characteristics of both fibers, in that most of the fibers will turn to ash, and some of the fibers will melt.
Synthetic Fibers – Aramids
Let’s now switch our attention to an exciting and more recently developed class of synthetic fibers, called the ARAMIDS. The ARAMIDS, in comparison to the TRADITIONAL synthetic fibers or even the NATURAL fibers, have some of the best fire resistant properties, and very few of the downfalls of traditional fibers.
Fabrics made from ARAMID threads are not only quite strong and abrasion resistant, but they are quite difficult to catch on fire, and don’t melt. In fact, when clothing made from ARAMID fibers, is exposed to fire, the individual threads actually swell to close off air spaces between them, and they form a carbonaceous char that’s extremely difficult to ignite. If you’re keeping score via the fire tetrahedron, this type of fabric helps to remove oxygen AND fuel from the equation.
Now, while clothing made out of ARAMID fibers sounds like the perfect costuming material for Fire Performers and Fire Safety Personnel, please keep in mind that there unfortunately are some downsides to these fabrics. For one, even though they don’t melt like the traditional synthetics, repeated exposure to heat and flame causes the fibers to degrade and eventually become stiff and brittle. Most fire performers have already experienced this phenomenon with their Kevlar wicks, which are made from ARAMID fibers
Another problem, as you may imagine with all this high technology, is it’s high cost and general lack of availability in clothing. Although, there are some manufacturers that have incorporated ARAMID fibers in various items of clothing, including flight suits and car racing suits. Please see the end of this video for web links.
Fabric Weight and Weave
Let’s switch from talking about the fibers to talking about the characteristic of fabrics, another important component affecting fire resistance. One important factor is the weave of the fabric. By this, I mean, how tightly woven together the individual fibers are. In terms of fabric weave, in general, the tighter the weave, the more protective it is against fire. As you can imagine, when the fibers and threads that make up the fabric are woven closer together, less oxygen can get to the individual fibers. And as we already know from the fire triangle and fire tetrahedron, oxygen is an essential component of fire ignition, as well as continued burning.
Similarly, the weight of a fabric is important in determining its fire resistance. In short, the heavier the fabric, the more fire resistant the material. For example, while both silk and denim are made of natural fibers and inherently fire resistant, because denim generally has a higher fabric weight, the silk will ignite much quicker than the denim.
A quick way to test the tightness of the weave and weight of any fabric is to hold it up to a bright light. If you can see light through the fabric, the weave or weight of the fabric is likely insufficient for fire protection.
Fabric Fit and Finish
Finally, how well the fabric fits against your skin is also a very important component in costume selection. Garments appropriate for Fire Performance and Fire Safety Personnel are generally snug fitting, as they prevent the buildup of oxygen underneath the clothing. Practically, they should be constructed so as they don’t block vision or movement. Furthermore, sleeves and pants should not be overly long and “floppy”. And Remember that dangling or fuzzy parts of clothing can easily catch fire as well because of the high amount of oxygen surrounding the fabric strands.
Fire Retardant Sprays
Well, what about fire retardant sprays? Fire retardant sprays can be useful in instances where you need extra ignition prevention. While these products delay ignition, it’s important to remember that they do not actually protect against heat transfer. Thus, synthetic materials can still melt onto your skin, and can even still burn you with their retained heat if exposed to flame or heat for a long enough period of time. It’s tempting to think that a Flame Retardant Spray can magically turn that awesome, but very flammable costume that you want to wear into appropriate Fire Performing clothing, but that’s just not true. Remember, eventually, almost any traditional fabric will catch on fire, regardless of it’s fire resistant treatment.
A few more notes about Flame Retardant Sprays – they generally take up to 24 hours to “cure” on the fabric being treated, and can also be washed out quite easily. In addition, most fire safety personnel are already using a tool treated with chemical Flame Retardant, in the form of Duvetyne, which is a cloth commonly used to extinguish unwanted fire.
Speaking of Duvetyne, let’s talk a bit more about this common fire prop extinguishing fabric. It goes by several different names and spellings. For instance, it’s variously known as “Commando Cloth”, “stage cloth”, or “Molton Fabric”. It’s an opaque, brushed cotton fabric, which comes in a multitude of colors, although you’ll generally see it in black or red. It comes in multiple weights, but the most appropriate weight for use in fire performance is 16 oz per linear yard. As we spoke about before, it’s treated with a water soluble Flame Retardant chemical. Because of this, it’s classified as a Non Durably Flame Retardant cloth (with the abbreviation NDFR), which basically means that the Flame Retardant can’t stand up to washing or very humid environments. So for instance, If your duvetyne gets soiled, and you have to clean it, it’s probably best to dry clean it. If it gets washed, it must be retreated with Flame Retardant. When buying duvetyne, make sure that it’s flame retardant to NFPA 701 standards.
One important factor to note while we’re thinking of duvetyne, is that while it’s treated with a fire retardant, that doesn’t mean that it’s not flammable. With just a spritzing of fuel and an ignition source, the duvetyne itself can catch fire, with disastrous results. In addition, especially with lesser weights of duvetyne and incomplete cutting off of the oxygen supply, watch for flames burning through the weave of the fabric when using it as a flame suppression tool.
So let’s summarize the topics that we talked about. In terms of fibers and threads, the most fire protective fibers are the Aramids (like Kevlar or Nomex or Carbon-X), followed by the Natural Fibers like cotton and wool. The least protective, and probably the most dangerous fibers include the traditional synthetic fibers, like polyester and nylon. In terms of fabrics, the thicker fabrics and those with tighter weaves, are the most protective against fire and heat transfer. Furthermore, clothing with a snug fit, appropriate length sleeves and pants, and smooth clothing without tears or “bells and whistles” are less likely to ignite.
The most important thing to remember is that there is no fabric that is “Fire Proof”, just fabrics that will protect you from burning longer than others. In a sense, they’re really just buying you time. And just because your skin is protected from igniting, it doesn’t mean that the heat from the fire won’t transfer through the clothing and still burn your skin.
For more information on the Fire Resistance of Fabrics, and Fire Retardant chemicals, please check out our links section at the end of this video, or on our website!
Well that it for this segment of the Flow Arts Institute Fire Safety Video series. For information on Fire Suppression using Fire Extinguishers, check out our next video segment![/fusion_builder_column][/fusion_builder_row][/fusion_builder_container]